Hardwood flooring has become a very popular choice in floor coverings. Traditional hardwood floors are made from a variety of wood planks and are placed in side-by-side relation to each other with the side edges being engaged with a tongue and groove arrangement. In order to secure the floorboard to the subfloor, nails are driven at an angle through a portion of the tongue of the plank and into the subfloor below.
One common substitute for hardwood flooring is laminate flooring. Laminate flooring is made to look like hardwood, but is easier to install and less expensive. Laminated flooring members typically comprise a decorative surface layer, a core, a balancing backing layer, and a wear layer, which are bonded together. The decorative surface layer can be made of a resin, such as, for example a melamine/aluminum oxide based resin. The decorative surface layer is typically bonded to a moisture resistant core that can be formed from, for example, a wood composition.
Conventional cores are made of high or medium density fiberboard that is typically saturated in resins to make them extremely hard. This allows the laminate flooring members to be cut with an edge profile, such as a tongue and complementary groove, as desired, for ease of installation.
The balancing backing layer is applied to the underside of the core to help stabilize the laminate flooring member and to act as another barrier against moisture entering the laminate flooring member from below. Most manufacturers saturate the backing layer with resin to resist moisture intrusion and to make the balancing backing layer more dimensionally stable. In conventional construction, laminate flooring members formed with a balancing backing layer are not typically glued directly to the sub floor.
The wear layer is applied to provide protection and stain resistance to protect the top of the laminate flooring member. The wear layer is typically clear so that the aesthetic appearance of the decorative layer, including any color and/or printed image, is not obscured by the overlying wear layer. However, while great care is taken to ensure that the laminate flooring member looks like real hardwood flooring, any damage to the wear layer makes it evident that it is not true hardwood flooring.
Another alternative to hardwood flooring is engineered hardwood. An engineered hardwood flooring board is conventionally constructed with an upper layer, a middle layer and a lower layer. The upper layer is typically formed of conventional hardwood flooring material. The middle layer is conventionally formed of a non-hardwood material, such as medium density fiberboard, high density fiberboard, particle board, plywood and the like. The lower layer can also be formed from a hardwood material similar to the upper layer, or it can be formed from a non-hardwood material that has specially selected properties, such as water resistance or rigidity.
The upper layer of the engineered hardwood flooring board is formed of hardwood to give the board the appearance of conventional hardwood flooring and to enable the engineered hardwood flooring board to be sanded when damaged, similarly to a hardwood-only board.
Further, the use of alternative material as the middle layer, or core of the board, greatly increases the dimensional stability of the board, which allows the production of engineered hardwood flooring boards that are longer and wider than conventional hardwood flooring boards.
The material in the middle layer can be formed or milled precisely prior to assembly into the engineered hardwood flooring board, which results in boards with tight tolerances that can easily be engaged with one another to form the flooring surface. In one example, similar to conventional hardwood flooring boards, engineered hardwood flooring boards can comprise a tongue and a complementary groove positioned on and extending along opposite sides of the board. Alternatively, the boards can be secured to one another using a snap-fit profile, similar to those used in the laminate flooring industry.
Conventional method of installation may cause some installation issues when the engineered hardwood flooring boards are engaged with a traditional tongue and groove connection. Notably, due to the increased density of the core material used in the middle layer portions of the core may be displaced when a nail or other fastener is driven into the top portion of the tongue, which causes a portion of the surface of the engineered hardwood flooring board to visibly protrude or bubble. In fact, this phenomenon often occurs in conventional hardwood flooring boards. What is needed is a flooring board and a method of installing an engineered hardwood flooring board that alleviates the problem of surface bubbling.